RhizoScan: A semiautomatic image processing system for characterization ofthe morphology and secondary metabolite concentration in hairy root cultures

We describe the application of the newly developed RHIZOSCAN software for a ccurate morphological analysis and determination of overall and local secon dary metabolite concentrations in two clones of Beta vulgaris throughout th e growth period. Local secondary metabolite concentrations may be determine d at any point in the root, and pigment gradients in each lateral root can be followed during culture and saved to the computer. Throughout the entire analysis process, an image appears in a graphical result window on the scr een, which enables visual evaluation of the numerical output at each stage of the analysis. Biosynthetic data on concentrations obtained by image anal ysis were validated by spectrophotometric analysis. The importance of deter mining appropriate scanning and analysis conditions (scanning resolution, b ackground color, threshold value, segmentation plane in the hue-saturation- intensity color system and pruning length) for obtaining accurate morpholog ical measurements is examined and the means of fixing these parameters is d escribed. Our results show that, using RHIZOSCAN, detailed and accurate inf ormation on root architecture and secondary metabolite concentrations can b e obtained in a short time. (C) 2000 John Wiley & Sons, Inc.